Kabushiki Kaisha Toyota Chuo Kenkyusho

Aisin Seiki Kabushiki Kaisha

Hidehiko Sugiyama

Osamu Asami

Yukio Yamada

Masana Hirai

Takao Imaeda

Tsutomu Kajino

Fumihiko Hoshino

Kiyoko Sarai

Chie Idekoba

Satoshi Fujita

Naoto Kagiyama

Masayoshi Momiyama

Takekazu Yamamoto

Yasumitsu Kondoh

Hiroko Uchiyama

A method of detecting nucleic acid utilizes hybridization between the nucleic acid to be detected which is present on an immobilizing support and a DNA probe which is complementary to at least a portion of the desired nucleotide sequence of the nucleic acid. The present DNA probe includes a hapten attached via a linker which a hapten is gibberellin or a gibberellin derivative. After hybridization by reaction between the nucleic acid to be detected and the DNA probe, the unreacted DNA probe is removed, and then labelled anti-hapten antibody is allowed to bind with the DNA probe of the hybrid and the labelling is used to detect the nucleic acid. Accordingly, stable detecting sensitivity may be achieved regardless of the label mixing ratio or labelling ratio, and thus regardless of the nucleotide sequence composition of the nucleic acid being tested.

Method of detecting nucleic acid

A highly thermostable polypeptide possessing protein disulfide isomerase (PDI) activity, a gene coding for the polypeptide and a process for producing the polyeptide are provided. The polypeptide possessing PDI activity is characterized by A) having a capability of catalyzing a disulfide exchange in proteins, B) recognizing mainly ribonuclease A as a substrate, C) having a suitable active temperature of 20.degree. to 70.degree. C., D) being stable at a pH value of 6 to 9, and E) having a molecular weight of about 60,000 to 62,000. Since it has a higher thermostability and exhibits a stable activity in a wider dithiothreitol concentration range as compared with the conventional PDI, it is possible to provide a novel enzyme active protein which can be advantageously used for a refolding reaction of certain proteins. Further, a process which enables the polylpeptide possessing PDI activity to be efficiently produced using Humicola insolens or a transformant transformed with an expression vector containing the above-described gene is also provided.

Polypeptide possessing protein disulfide isomerase activity gene

A highly thermostable polypeptide possessing protein disulfide isomerase (PDI) activity, a gene coding for the polypeptide and a process for producing the polypeptide are provided. The polypeptide possessing PDI activity is characterized by A) having a capability of catalyzing a disulfide exchange in proteins, B) recognizing mainly ribonuclease A as a substrate, C) having a suitable active temperature of 20.degree. to 70.degree. C., D) being stable at a pH value of 6 to 9, and E) having a molecular weight of about 60,000 to 62,000. Since it has a higher thermostability and exhibits a stable activity in a wider dithiothreitol concentration range as compared with the conventional PDI, it is possible to provide a novel enzyme active protein which can be advantageously used for a refolding reaction of certain proteins. Further, a process which enables the polypeptide possessing PDI activity to be efficiently produced using Humicola insolens or a transformant transformed with an expression vector containing the above-described gene is also provided.

Polypeptide from Humicola insolens possessing protein disulfide

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Nagoya, Japan

Hidehiko Sugiyama